PLEASE HELP!

Got a brand new DPF coming. Will get installed and update thread on whether or not it fixed the issue.

 

Whats your reasoning on how temp sensors can cause high backpressure? My truck does a forced regen with zero issues. I mean for the 250 bucks for 3 new sensors, I wont hesitate. I have a dpf coming, so my thought is try that first. Nothing with dpf parameters looked out of place to the dealer besides 4.04 reading from pressure sensor. That 4.04 reading corresponds with my dpf soot level gauge. Its just odd that a cleaned and wire tested DPF is running that high. My truck has not asked for a parked regen yet. Soot level is getting to just before the "2" and then backs down to just past the "triangle" There isnt much else to replace by now. So I know the systems working, its just the soot level is way higher than it should be.

 

I believe the reading of 4.04 was volt output from pressure sensor, not psi reading. Here is what I have from dealer on 3/27

Reassemble DPF DIFF pressure sensor tubes and sensor. Run Engine at Hi RPMS and monitor DPF. Diff reading .27 at 2100 rpms and .12 at idle. Agrees with 70% soot load report. Hook up manual exhaust back pressure gauge and run at high rpm. Agrees with DPF pressure 1.3psi. Run Regen and check where soot load is at end and what diff pressure is at High RPMS. Went through with good temps 221 @T2. Soot load went down to 11%. Diff pressure at .44 at high idle hot after regen and .25 at hot idle. Check turbo motor effort hot ok 20-50%.

on 3/29 I have this

Hook up pressure gauge to DPF and check exhaust back pressure at 2100 rpms 1.4psi. Remove Bellow and check pressure again 1.2psi. Not a restricted SCR

 

I still am curious about your temp sensor theory. I am open to change them out. I am curious as to why you think I should

 

this whole ordeal has been going on since dec. There has been multiple readings for all the sensors. This is a Volvo dealer. Volvo wants the dealer to swap injectors. Thats where I draw the line. For me, there isnt much that can create back pressure in the exhaust. We ruled out the SCR, that leaves the DPF. The dealer doesnt think its the DPF since it was recently cleaned and flow tested to oem spec. When they had it apart, I was able to look in from where the DOC connects to exhaust. I could see the turbo, no restrictions. I replaced the bellows and I know there is no restrictions there. whats left besides DPF to cause restriction?